In conventional dentistry procedures it is customary to install one or more pins into broken down teeth or into teeth to which orthodontic appliances are being applied. The treatment of broken down teeth is of course more prevalent, and the present invention will be discussed primarily in conjunction with restorative techniques for treating teeth where the nerve is still alive. It will be understood, however, that the invention is also applicable to orthodontic techniques or to non-vital teeth.
As is well known, the conventional procedure is to initially drill one or more relatively deep holes in the dentin portion of the tooth undergoing repair. The drilling can be carried out, for example, by utilizing a typical dental twist drill. The dentist then screws in a small, screw-threaded anchor into each of the holes leaving a portion of the screw-threaded pin sticking out of the hole. The remainder of the screw-threaded pin is retained in the dentin as the anchor.
Illustrative U.S. patents pertaining to anchor retention pins include the following:
Baker--U.S. Pat. No. 3,364,575 PA1 Tieche--U.S. Pat. No. 4,142,293 PA1 Chan--U.S. Pat. No. 4,187,611 PA1 Smith--U.S. Pat. No. 4,189,834 PA1 Weissman--U.S. Pat. No. 4,202,101 PA1 Carse--U.S. Pat. No. 4,219,620
A commercially available screw pin is sold by Pulpdent Corporation of America as "Stabilok" screw-pins under U.S. Pat. No. 4,189,834.
A number of commercially available dental drills have been employed for making the holes or channels in the dentin which are required for the anchor pins.
In accordance with present day practices, therefore, two instruments are needed: a drill, e.g. a twist drill; and a diameter-coordinated screw pin. After the twist drill digs its deep hole or channel, the path of insertion must again be found in order to screw in the screw-threaded anchor pin. Since the drilled hole is very tiny, in general being on the order of 0.021 inch or so, plus or minus a few ten thousandths of an inch in diameter. If the screw-threaded pin is not inserted with its long axis exactly parallel and in line with the orifice and the long axis of the hole, it is difficult, if not impossible, to successfully screw the pin into the hole. Moreover, sometimes the drilled hole or opening is in a difficult location for good accessibility or visibility. At times, the drilled hole or channel is obfuscated by debris or saliva.